The Automobile Association has revealed the peak days for people travelling.

It says people traditionally return from their holidays on January 2 and 3 - the peak days for travelling.

AA chief policy officer Simon Douglas says the biggest traffic hotspots are expected to be north and south of Auckland, as that is where there are "the biggest population centres".

Simon says there could also be some congestion around Wellington, although the opening of Transmission Gully had seen traffic flow improve "considerably" in recent years.

"If you can leave before 10am in the morning or after 4pm in the afternoon, you'll avoid the worst of those peaks."

Simon says a huge maintenance programme has also been rolled out by the government this summer, further affecting traffic.

He says there has also been "quite a bit of variation" in the weather conditions over the Christmas period and there are heavy rain warnings ahead.

"If you're planning to drive through those events, please if you can avoid being on the road at the worst of times."

If people do have to drive in adverse conditions, he advises that they allow extra journey time and keep an adequate distance from the car in front of them.

MetService says rain will be approaching the western part of the country from the later part of Thursday and into Friday.

Heavy rain watches are already in place for several parts of the South Island and Mount Taranaki in the North.

MetService says more wind and rain watches could be added.

Holiday road toll

The Christmas holiday road toll has risen to seven following the death of a woman in a quad bike crash in Waikato.

Emergency services were called to Rauparaha Street in Marokopa late yesterday afternoon, after witnesses reported seeing her come off the bike.

Last year, 21 people died on the roads over the Christmas-New Year holiday period.

-RNZ.